<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <title>console Node.js v0.8.12 Manual &amp; Documentation</title>
  <link rel="stylesheet" href="assets/style.css">
  <link rel="stylesheet" href="assets/sh.css">
  <link rel="canonical" href="http://nodejs.org/api/stdio.html">
</head>
<body class="alt apidoc" id="api-section-stdio">
    <div id="intro" class="interior">
        <a href="/" title="Go back to the home page">
            <img id="logo" src="http://nodejs.org/images/logo-light.png" alt="node.js">
        </a>
    </div>
    <div id="content" class="clearfix">
        <div id="column2" class="interior">
            <ul>
                <li><a href="/" class="home">Home</a></li>
                <li><a href="/download/" class="download">Download</a></li>
                <li><a href="/about/" class="about">About</a></li>
                <li><a href="http://search.npmjs.org/" class="npm">npm Registry</a></li>
                <li><a href="http://nodejs.org/api/" class="docs current">Docs</a></li>
                <li><a href="http://blog.nodejs.org" class="blog">Blog</a></li>
                <li><a href="/community/" class="community">Community</a></li>
                <li><a href="/logos/" class="logos">Logos</a></li>
                <li><a href="http://jobs.nodejs.org/" class="jobs">Jobs</a></li>
            </ul>
            <p class="twitter"><a href="http://twitter.com/nodejs">@nodejs</a></p>
        </div>

        <div id="column1" class="interior">
          <header>
            <h1>Node.js v0.8.12 Manual &amp; Documentation</h1>
            <div id="gtoc">
              <p>
                <a href="index.html" name="toc">Index</a> |
                <a href="all.html">View on single page</a> |
                <a href="stdio.json">View as JSON</a>
              </p>
            </div>
            <hr>
          </header>

          <div id="toc">
            <h2>Table of Contents</h2>
            <ul>
<li><a href="#stdio_console">console</a><ul>
<li><a href="#stdio_console_log_data">console.log([data], [...])</a></li>
<li><a href="#stdio_console_info_data">console.info([data], [...])</a></li>
<li><a href="#stdio_console_error_data">console.error([data], [...])</a></li>
<li><a href="#stdio_console_warn_data">console.warn([data], [...])</a></li>
<li><a href="#stdio_console_dir_obj">console.dir(obj)</a></li>
<li><a href="#stdio_console_time_label">console.time(label)</a></li>
<li><a href="#stdio_console_timeend_label">console.timeEnd(label)</a></li>
<li><a href="#stdio_console_trace_label">console.trace(label)</a></li>
<li><a href="#stdio_console_assert_expression_message">console.assert(expression, [message])</a></li>
</ul>
</li>
</ul>

          </div>

          <div id="apicontent">
            <h1>console<span><a class="mark" href="#stdio_console" id="stdio_console">#</a></span></h1>
<pre><code>Stability: 4 - API Frozen</code></pre>
<ul>
<li>{Object}</li>
</ul>
<!--type=global-->

<p>For printing to stdout and stderr.  Similar to the console object functions
provided by most web browsers, here the output is sent to stdout or stderr.

</p>
<h2>console.log([data], [...])<span><a class="mark" href="#stdio_console_log_data" id="stdio_console_log_data">#</a></span></h2>
<p>Prints to stdout with newline. This function can take multiple arguments in a
<code>printf()</code>-like way. Example:

</p>
<pre><code>console.log(&#39;count: %d&#39;, count);</code></pre>
<p>If formatting elements are not found in the first string then <code>util.inspect</code>
is used on each argument.  See <a href="util.html#util_util_format_format">util.format()</a> for more information.

</p>
<h2>console.info([data], [...])<span><a class="mark" href="#stdio_console_info_data" id="stdio_console_info_data">#</a></span></h2>
<p>Same as <code>console.log</code>.

</p>
<h2>console.error([data], [...])<span><a class="mark" href="#stdio_console_error_data" id="stdio_console_error_data">#</a></span></h2>
<p>Same as <code>console.log</code> but prints to stderr.

</p>
<h2>console.warn([data], [...])<span><a class="mark" href="#stdio_console_warn_data" id="stdio_console_warn_data">#</a></span></h2>
<p>Same as <code>console.error</code>.

</p>
<h2>console.dir(obj)<span><a class="mark" href="#stdio_console_dir_obj" id="stdio_console_dir_obj">#</a></span></h2>
<p>Uses <code>util.inspect</code> on <code>obj</code> and prints resulting string to stdout.

</p>
<h2>console.time(label)<span><a class="mark" href="#stdio_console_time_label" id="stdio_console_time_label">#</a></span></h2>
<p>Mark a time.

</p>
<h2>console.timeEnd(label)<span><a class="mark" href="#stdio_console_timeend_label" id="stdio_console_timeend_label">#</a></span></h2>
<p>Finish timer, record output. Example:

</p>
<pre><code>console.time(&#39;100-elements&#39;);
for (var i = 0; i &lt; 100; i++) {
  ;
}
console.timeEnd(&#39;100-elements&#39;);</code></pre>
<h2>console.trace(label)<span><a class="mark" href="#stdio_console_trace_label" id="stdio_console_trace_label">#</a></span></h2>
<p>Print a stack trace to stderr of the current position.

</p>
<h2>console.assert(expression, [message])<span><a class="mark" href="#stdio_console_assert_expression_message" id="stdio_console_assert_expression_message">#</a></span></h2>
<p>Same as <a href="assert.html#assert_assert_value_message_assert_ok_value_message">assert.ok()</a> where if the <code>expression</code> evaluates as <code>false</code> throw an
AssertionError with <code>message</code>.

</p>

          </div>
        </div>
    </div>
    <div id="footer">
        <ul class="clearfix">
            <li><a href="/">Node.js</a></li>
            <li><a href="/download/">Download</a></li>
            <li><a href="/about/">About</a></li>
            <li><a href="http://search.npmjs.org/">npm Registry</a></li>
            <li><a href="http://nodejs.org/api/">Docs</a></li>
            <li><a href="http://blog.nodejs.org">Blog</a></li>
            <li><a href="/community/">Community</a></li>
            <li><a href="/logos/">Logos</a></li>
            <li><a href="http://jobs.nodejs.org/">Jobs</a></li>
            <li><a href="http://twitter.com/nodejs" class="twitter">@nodejs</a></li>
        </ul>

        <p>Copyright <a href="http://joyent.com/">Joyent, Inc</a>, Node.js is a <a href="/trademark-policy.pdf">trademark</a> of Joyent, Inc. View <a href="https://raw.github.com/joyent/node/v0.8.12/LICENSE">license</a>.</p>
    </div>

  <script src="../sh_main.js"></script>
  <script src="../sh_javascript.min.js"></script>
  <script>highlight(undefined, undefined, 'pre');</script>
  <script>
    window._gaq = [['_setAccount', 'UA-10874194-2'], ['_trackPageview']];
    (function(d, t) {
      var g = d.createElement(t),
          s = d.getElementsByTagName(t)[0];
      g.src = '//www.google-analytics.com/ga.js';
      s.parentNode.insertBefore(g, s);
    }(document, 'script'));
  </script>
</body>
</html>

